1. Field of the Invention
The present Invention relates to the connector for connecting the tubes, which are used to protect the electric wires or cables and so on.
2. Description of the Prior Art
The tubes are buried under the earth with the necessary water-proof properties, wherein, as shown in the FIG. 5, there must be a strict water-proof between the tube-connector and the tube. The FIG. 5 shows the connector for connecting the tubes of various types 101 made of synthetic rubber, wherein the tube 102 provided with waves of synthetic resin having a protruding device 102a in the shape of a spiral around the tube is to be screwed onto one part of the tube-connector 101. Subsequently, the tube 103 which does not have a protruding device around it is inserted into another part of the tube-connector 101, which connector is tightened by the band 104. Consequently, the sealing tape 105 is tightly rolled around on the side of the tube 102 with waves, of the tube-connector 101, above which the water-tight protection tape 106 is firmly rolled and furthermore, the end of the water-tight protection tape 106, which has been rolled, is to be rolled while being pressed, using the vinyl tape 107. For the use in the exposed place, the vinyl tape 107 should be rolled on the whole part of the tube-connector 101.
Therefore, between the tube with waves 102 and the tube-connector 101, at least three-fold water-proof must be applied because of its shape, thus involving a lot of troubles for the connecting operation.
The example shown in the figure is a connector for connecting various tubes, wherein the above-described water-proof structure must be applied onto one end part, however in the case of the straight tube-connector there must be formed water-proof structures on both ends, the water-proof having to be done in a plurality of points depending on the types of the tube-connectors, thus involving more troubles and time.
The main purpose of the present invention is to provide a tube-connector, which enables a connecting operation to be done very easily, wherein the water-proof properties are very good.
In other words, a tube-connector of synthetic resin and rubber having a connecting part for connecting by inserting the end part of the tube must be provided, wherein the tube-connector comprises the expanding body which expands absorbing water, on the surface facing the tube in the above said connecting part.
The above-mentioned expanding bodies may be formed of water-swelling rubber or high water-absorbing resin (water-swelling polymer), for example, comprising fibers, powders and films in the shape of a metal. In the formation of the synthetic resin or rubber, pressure and heat may be applied, preferably comprising the flexible materials capable of being increased and decreased in terms of volume, being made of suitable heat resistant materials, for example, there may be used sponge materials or non woven cloths, containing or mixed with high water-absorbing resin or water-swelling rubber.
This means, in order to connect the tubes using the above described tube-connector, the end part of the tubes has only to be screwed, pressed or inserted into the connecting part of the tube-connector suitably according to their shapes. Afterwards, the expanding bodies formed on the facing surface of the connecting part become swollen with water, which water has come from outside, thus providing air-tightness, being pressed onto the surface of the tube bodies.
Therefore, it is not necessary to carry out the complicated operations like rolling various types of tapes there as conventionally has been done, providing for easy connecting operations so that the prompt connecting operation can be expected. Furthermore, when water is absorbed, the expanding body becomes expanded to be large, thus it is possible to obtain air-tightness surely while there is a good water-proof property. In addition, the expansion is done automatically, the process is very easy without any need of force like tightening.
Furthermore, when the expanding body comprises high water-absorbing resin, once it is expanded by water absorption, it is made hard to remove water even when adding pressure, and as there is water under the earth where the tubes are buried, air-tightness can be surely maintained.
As there is formed an expanding body, there is no need to have other parts to obtain water-proof and it is easy to control, for example, the products and operations are easy as described above.
A thermoplastic resin may be added into the expanding body, which resin can be melted by heat at the time of forming the expanding body. For example, by mixing into the expanding body made of non woven cloth as a fiber in an appropriate proportion, the thermoplastic resin may be melted at the time of formation and subsequently cooled and set so that there can be more unity with the forming material and its shape will be adjusted to any complicated form such as the one having threads of the screw. This enables sure insertion into the connecting part, while obtaining the effects of making the even expansion possible.
The sheet material may be inserted between the above described expanding body and the forming material. The sheet material may be ventilated like cloths or may be a film, which cannot be ventilated but may be the one that gets united with the forming material upon melting at the time of formation. At this time, on the surface of the sheet in contact with the expanding body there is applied an adhesive agent, thus suitably providing for the unity with the expanding body.
For instance, when the non woven cloth is used to form the expanding body, the material is liable to penetrate the expanding body at the time formation and also the expanding body tends to be carried away by the pressure at the time of formation wherein the sheet material deters the penetration of the material, thus providing for the suitable protection of the expanding body while serving as a buffer. Therefore, there can be obtained the effects of unifying the devices in such a state that the layer structure is conserved wherein a high water-absorbing resin of the expanding body can be swollen.
Other objects of the present invention will be easily clarified according to the below mentioned examples.